PTPN11 mutations in JMML, NS/MPD, and NS/LS. The middle sections of both panels show wild-type SHP2 amino acid residue at each position. (A) Residues located within the N-SH2 domain encoded by exon 3. (B) Residues located within the portion of the catalytic domain encoded by exon 13. Amino acid substitutions documented in JMML and NS/MPD (italics), and in NS and LS (italics) are shown above and below the wild-type SHP2 sequence, respectively. Del indicates a deletion of this amino acid. Digits in parentheses indicate the numbers of individuals with JMML, NS/MPD, or NS carrying a specific mutation. Novel mutations are identified by asterisks. Whereas virtually all mutations in JMMLand NS/MPD are located within these confined regions, mutations associated with NS alone alter other residues of SHP2 in approximately 50% of the cases.9 Our data, updated to January 2005, includes 107 cases with JMML, 19 with NS/MPD, 181 with NS, and 42 with LS.
